A thermal lance generally corresponds to a long, narrow tube with an oxidizable outer body and comprising along the entire extension thereof one or more oxidizable inner components, such as solid wires. The inner bodies are distributed inside the outer body, with gaps therebetween. In general, a thermal lance measures from 8 to 50 mm in diameter and from 1 to 12 m in length.
At their ignition end, thermal lances reach temperatures in the order of 3,500° C. to 5,530° C., and thermal lance consumption times are in the order of 0.2 to 5 meters per minute, when the pressure of the oxidizing gas is comprised from 392.3 kPa to 980.7 kPa. However, the energy that a lance can usually generate is lost in melting the lance itself, for example the heat of combustion of iron is of 4.23 KJ/g and when burning a standard thermal lance, generally containing three grams of iron, one gram burns quickly while the other two grams melt without combusting, which ultimately translates into part of the energy generated by the gram that did combust is lost in melting the other two grams that did not combust. Since the energy is spent in the lance itself, there is much less energy available for the work at hand.
Invention patent registration no. 44,086 discloses a device for piercing and opening passages in clay in melting furnaces, used in the smelting of ores, formed by an hollow outer tubular body, having in its inner area a symmetrical longitudinal body having a smaller length and made of steel, with a central opening and at least four preferably convex vertexes, the outer walls of which are concave and straight, the inner walls of which are convex and straight; furthermore, said vertexes are joined with the inner wall of the tubular body, at least four cavities being formed which allow the entry and exit of oxygen delivered through the cylinder.
Patent document GB1288931 discloses a thermal lance having a metallic tubular body comprising a plurality of cylindrical wires therein, which are welded to the adjacent edges and take up all the inner space of the tube, only some passages remaining for circulation of the oxidizing gas.
In turn, patent document GB2151530 relates to a thermal lance comprising an outer metal conduit being made of aluminum or iron or an alloy containing predominantly iron, a inner metal conduit and/or a number of metal rods located within the outer metal conduit, the inner metal conduit and/or metal rods being made of aluminum or iron or an alloy containing predominantly steel, such that at least one of the conduits or one of the rods is made of aluminum and at least one of the conduits or one of the rods is made of iron or an alloy containing predominantly steel; the lance including a holder at one end, which is provided with a valve through which, in use, the oxygen may be admitted to pass through the lance to the other end for the ignition.
U.S. Pat. No. 4,401,040 discloses a thermal torch comprising: an elongate burner pipe having a longitudinal axis and open at both ends; a bundle of elongate consumable rods arranged within the interior of said burner pipe, said rods having longitudinal axes parallel to and coextensive with said burner pipe and said rods having substantially identical cross-sectional configurations, said rods arranged to form at least a first and a second pressure fuel passage, the first passage extending between the inner surface of said burner pipe and the outer surfaces of the ones of said rods which are arranged adjacent the inner surface of said burner pipe, and the second passage extending between the inner surfaces of the ones of said rods which are arranged adjacent the inner surface of said burner pipe and the outer surfaces of the remainder of said rods.
Patent document CH617613 relates to an oxygen lance having a hollow tubular shell internally comprising particles that can be melted and have irregular and regular shapes, the particles being fixed with adhesive and the core of the lance is permeable to oxygen.
Patent document GB1317540 discloses a thermal lance comprising a plurality of cylindrical metal wires enclosed in a hollow tubular body, the cross-section of the tubular body being reduced to firmly locate the metal wires therein.
As can be seen, in the state of the art, there are different types of thermal lances. However, there is still a need to provide more efficient thermal lances both in terms of the effective heating capacity they develop and in terms of the flexibility capacity, as required, from the most rigid to the most flexible. Furthermore, there is a need to provide lances that allow a higher concentration of the energy generated, in which the oxidizing gas or oxygen stream can be managed at will and integral use of the lance is achieved.
Based on the foregoing, an objective of the present invention is to develop a thermal lance that increases the effective heating capacity developed by the lance and that concentrates the energy so as to be able to control the work thereof.
At the same time, another objective of the present invention is to develop a lance that can be operated using different oxygen streams, keeping the combustion thereof level and constant, as needed at the time of the operation thereof.
Another objective of the present invention is to develop a thermal lance having greater flexibility, for example, being able to bend.
Yet another objective of the present invention is to develop a thermal lance that does not need external elements for the fixing and securing of its parts, i.e., having only integral fixing elements without having to use welds, screws, wedges, or external pressing, making the inner elements narrower.
Furthermore, another objective of the present invention is to develop a lance that does not melt at high temperatures above 1,400° C., such that it continues combusting above those temperatures.
Likewise, another objective of the present invention is to provide a thermal lance that is readily susceptible to coupling to another thermal lance, for the purpose of preventing losses of lance remnants at the time the lances are being used.